A device which controls the voltage and current being delivered to a capacitor or battery.

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3answers
72 views

Will a dual car charger that shows a maximum output of 2000mA produce a 2.1A current?

I have a dual car charger that states input is 12-24VDC and Output is maximum of 2000mA, but it is supposed to have one port charge at 1A and other port charge at 2.1A. Is the 2.1A output possible ...
0
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4answers
88 views

What is this electronics component?

What is the yellow component shown here? This is off a Outlet USB phone charger.
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1answer
48 views

LiPo Charger question [closed]

I'm not into electronic so this is why I ask people who know. I have an opportunity to buy a 5,000 mAh LiPo charger but I will use it to charge up to 14.8V 8,000 mAh batteries. Will it charge the ...
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1answer
27 views

What is a good NiMH charger? [closed]

I have some (cheap/old?) batteries that I need charged. The problem is, the chargers I have keep charging them until they get overcharged and lose their capacity. I already ruined 4 ...
1
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2answers
74 views

Why one transistor switches on first than other

In the circuit diagram given below we have two transistors. And in the article it is given that one transistor will turn on first. Why this transistor turns on first
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0answers
31 views

homemade hub dynamo usb charger

I just made an usb charger to connect to my hub dynamo. ->voltage rectifier -> smoothing capacitor -> low voltage drop 5V regulator -> female usb port So now I can power / charge my mobile phone and ...
1
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4answers
91 views

Will voltage or current determine a diode drop for this battery charging circuit?

I am using a li-ion battery charger IC that regulates an output to 4.2V. I have a schottky diode in series with the output that then connects to the battery. How do I determine the voltage drop? If ...
-1
votes
1answer
68 views

What do B+ and C+ mean on the wires of a Lifepo4 battery pack?

I bought this Lifepo4 battery pack. It came with its own charger. The seller told me the charger can be connected directly to the battery. There are 4 cables coming out of the battery: C+, C-, B+ and ...
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1answer
58 views

Efficient power utilization by MPPT battery charger

I am designing an MPPT solar charge controller to get more efficiency out of my system. At the moment I am at the conceptual stage and I have some questions about MPPT battery charging in general. ...
-1
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1answer
97 views

Transmitting 12v DC over a long wire

I'm trying to charge my laptop through a 12V battery and 12-19V adapter over a long wire but I've noticed that the adapter makes some noise and doesn't work. On the other hand when I connect it close ...
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2answers
53 views

DC output of phone charger [duplicate]

I have a nokia phone charger which has the following specifications: Input: AC 100-240 V, 50-60 Hz, 100 mA Output: DC 5.0 V, 350 mA When I checked the output of the charger with a multimeter it ...
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0answers
48 views

LiPo combination usb/dc/solar charger + fuel monitor

I'm trying to roll several LiPo boards available on Sparkfun/Adafruit into one multipurpose board. Not a very ambitious project I know, but I'd really like an all in one. I've seen Sparkfun's LiPo ...
0
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1answer
49 views

Can someone tell me if this topology for a crude battery charger is sound? Block diagram included

I am making a portable phone charging battery for fun. I have a micro USB input that ties to a 5V - 4.2V buck converter to charge a li-ion battery. The IC is made to charge batteries so I think that ...
0
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1answer
93 views

Can I use a 7805 as a current regulator?

Can I use 7805 as current regulator? My input is 12-14 V DC (battery) and I require output 5V and 500mA or adjustable. My background is CS so unaware of these ICs. I have searched LM317 and LM338 but ...
2
votes
2answers
168 views

Is it ok to use an old phone as an universal battery charger?

We know that a charger is just an adapter that supplies a constant voltage (5 volts usually). The actual charging circuit is in the phone itself. With a bit of soldering and wiring, can I use my old ...
0
votes
1answer
67 views

Battery charging: Absorption Charge Stage

I need some help in understanding basic battery charging. I read about the three common stages: Bulk Charging, Absorption Stage and Float Stage, but I can't understand exactly what the controller does ...
2
votes
1answer
81 views

LiPo use while charging: two cells (one charging, one under load)

I'm trying to figure out how to power my project using LiPo batteries and a solar charging circuit. The project will draw up to 2A at 3.3V. I did a search for IC LiPo charging chips that also allow ...
1
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2answers
80 views

Charging 12V SLA from Single Solar Cell

I'm interested in charging a 12V Sealed Lead-Acid battery from a single monocrystalline solar cell. The solar cell's voltage is only 0.5V at maximum power point, but it supplies 8A. I will need a 32X ...
0
votes
1answer
75 views

Trigger charge in Android phone using a PIR

I want to use my android phone + 1 PIR as a poor man's home alarm. I need the phone to be triggered somehow when the PIR detects motion. I was looking at the IOIO board. But wouldn't even be easier ...
1
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1answer
83 views

Is the DESIGN of an MPPT Solar charger SUPPORTING combination with regular battery charger on the LOAD side? [closed]

I just got my "LCD 30A MPPT Solar Panel regulator" for my caravan, but connecting it raised an issue. It looks like this: ...
2
votes
2answers
127 views

How do we charge a small 12V battery from a large 12V battery bank

In a youth organization that I am part of we are building a traveling stand alone system, which will be put up on various fairs and music festivals. On one of the festivals there is a wish that we can ...
1
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3answers
90 views

Please help me understand this charging algorithm

I am trying to plan a stand alone system, and for that I will need a charge controller. I am looking at a few models from the company MorningStar. I have understood what MPPT is, and decided to not ...
1
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1answer
126 views

Charging 7.4V Li-Ion battery

I'm making a battery out of two 3.75V Li-Ion cells to go into a speaker system that powers an amplifier. I was wondering on the PCM, how many volts would be max to charge these cells? The cells I have ...
0
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1answer
48 views

ICSwitching between solar panel and batteries

I would like to charge the NiMH batteries, when there is excess power from the solar power and use the power stored in the batteries, when I need it (to drive a motor and at night). I have the ...
0
votes
2answers
90 views

What are the downsides of using a LM7805 with a 11.1v Li Ion Laptop battery to charge a USB device?

I want to use my thinkpad battery(11.1v) hooked up to a LM7805 to charge a USB Device. What are the downsides to such a setup?
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2answers
202 views

Charging 2 Li-Ion Batteries via a single charger

I'm currently building a portable USB charger. It uses 2 Li-ion batteries in series connected to a USB port via a 5V regulated buck converter. While a single Li-ion battery would suffice for most ...
0
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1answer
72 views

What does 'Braked Voltage' mean on a charge controller?

Here is the complete specs of the controller. Battery rated voltage: 12v Wind turbine rated power: 300w Wind turbine braked voltage: 15v Recover voltage: 13.5v Quiescent dissipation: <8ma ...
0
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1answer
71 views

POWER SUPPLY / CHARGER [duplicate]

I have a 14.4v NI CD power drill with a charger that outputs 18v 400mA (original charger for drill) but the charger supply lead no longer works. Looking to get a replacement but finding it difficult ...
0
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1answer
81 views

Charging of Cell Phone Batteries and Electricity! [closed]

Does charging an already charged battery of cell phones/laptops consume electricity? Whenever my cell phone becomes fully charged while charging, it asks me to remove the charger from the socket to ...
0
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1answer
113 views

Multi port usb charger

I want to make a multi port usb "dumb hub" kind of like this. My question though is if I have a 5v 2500mA power supply, can I just daisy chain them together with out the fuses then connect it to the ...
1
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2answers
66 views

Need to charge a lithium power pack from USB

I need to charge a small lithium power pack from a device that was originally charged using a 5v USB connection. The connector on the device is damaged so I need to charge the power pack directly. ...
0
votes
1answer
209 views

Powering circuit from 12V with stand-by battery + solar charger

I did some research but I haven't been able to find the information that I really want. I am building a home made security system consisting of several IP cameras. Brownouts are very frequent so I ...
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votes
1answer
79 views

humming of a mobile phone charger [closed]

Why do a mobile phone charger (without mobile phone attached to it) constantly hums when kept plugged into A.C. outlet and the moment mobile phone is plugged into charger, humming goes. Why so ?
5
votes
3answers
720 views

How to make a voltage multiplier of 1.075

I have an 80v power supply that's rated to put out 18 amps, and I'm planning on using it to charge an 80v battery pack. Unfortunately the pack's charge voltage is 86v, so what I'm wandering about is ...
0
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1answer
86 views

How can I disconnect a Battery Charger from the Battery while not Charging

I have a LiIon Battery Charger IC which will draw around 50µA when not needed, see circuit 1. This is a lot of current for no work in my opinion. Now I search for a solution how I can disconnect the ...
1
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0answers
57 views

Why does the QI charger I recently bought only charge for a couple of times? [closed]

I recently bought a QI compatible charger for my Nexus 5. On the box it states, that the wireless charges up to 500 times. I don't understand why the charger is only able to charge my phone 500 times. ...
3
votes
2answers
136 views

What might cause audible noise in an inductive charging system?

I have a pair of Qi-compatible wireless charging pads, and I've noticed that when a device is charging, the pad will emit a quiet but noticeable squeal in a relatively high frequency range. Perhaps ...
3
votes
1answer
98 views

How do I smooth current dips on a USB charger?

I've got a USB charger that I want to use to charge a phone. For about 35 seconds it outputs enough current for the phone to detect it and start charging, then for an instant (no equipment to read ...
4
votes
2answers
201 views

Hacking wall wart as a USB charging station

I would like to modify an old power supply to have a USB A female adapter so that I could use it to charge any device. I plan to split out the power lines from an adapter that is: Input: 100-240V - ...
1
vote
1answer
131 views

Modding a charger into a power supply + charger?

I am making a handheld radio telescope which needs 13-18v to power and currently runs off 2 9V batteries. However it eats power like mad, drains them so hard that it actually needs to be recalibrated ...
1
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2answers
388 views

Can I use a 0.7A charger in place of a 1A charger? [closed]

One problem that I usually come across is the current ratings on mobile phone chargers. Right now, I need a 1A charger (which was shipped with my phone) and I have a 0.7A charger handy. Both the ...
1
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3answers
212 views

How safe is this?

I'm wondering how safe this is to make and to build into my setup. :P A bit afraid of it exploding. http://www.apartmenttherapy.com/make-your-own-batterypowered-u-100359
1
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2answers
193 views

powering +5v device with usb and/or battery

I made a PCB with an arduino clone and a tiny motor driver. The arduino clone itself needs +5 volt power supply, so I decided to use a DC/DC boost converter to boost a 3.7 volt Li-Ion battery to +5 ...
0
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0answers
52 views

Li-ion and Li-po charger current leak from input pin

According to the block diagram below of TI BQ24074 Li-ion/Li-po charger, could some current (even tiny) leak from BAT/OUT to IN when IN is disconnected from its source ? I noticed the Q1 transistor ...
1
vote
1answer
519 views

Emulating a USB Standard Downstream Port Charging application

I have am using an LM5017 to step down a relatively high voltage solar panel (VOC over 90V) to 5V. I have bench tested my circuit and it is providing good buck regulation with input voltages up to ...
1
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1answer
52 views

Looking for some solar panels to go with this project

I've been looking around for some solar panels for a little homemade solar phone charger project. I recently found a portable phone charger project from a student at Cal Poly which I'm hoping I can ...
1
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2answers
98 views

Combined chip with LDO and Buck, what use?

I am searching for a Li-polymer 1A charger with a 3V regulated output. I have found Linear LTC355x serie but can't, after reading many "LDO vs Switching" debates, understand the use of both on the ...
4
votes
4answers
564 views

Charging phone battery with a high current source

I am working on a project which the goal is using some android tablets to show pieces of video file to form a multiscreen. One electronic problem that I have faced is: The tablets should be always ...
1
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3answers
244 views

Charging batteries directly from 117 volt wall socket

It has occurred to me that almost no battery charger would be required if the battery pack was of the same voltage as grid supplied power. I build electric bikes, and the voltage on these has been ...
1
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0answers
150 views

LEDs dim when using LM317 [closed]

I'm trying to construct a very simple emergency light system, but when I create the path represented by the red path in the image bellow, the LEDs lose brightness. Without this path I get 3.5v (with ...